What primary method of inspection assesses the physical condition of bridge materials?

The primary method of inspecting the physical condition of bridge materials is through physical inspection. This method involves a hands-on examination of the bridge components to assess their condition, including looking for signs of wear, corrosion, cracking, and other visible defects. Physical inspection is critical in identifying issues that may not be visible through other means.

In contrast, while visual inspection plays a significant role in early assessments, it focuses on what can be seen from a distance and may not capture more severe underlying problems. Mechanical inspections typically involve the use of tools or devices to measure or test materials but do not encompass the overall physical evaluation of bridge components. Auditory inspections, which involve listening for sounds that indicate problems, are less reliable for assessing physical integrity compared to more direct methods. Therefore, the physical inspection is essential for accurately determining the state of bridge materials and ensuring functionality and safety.